Embolic framing microcoils

ABSTRACT

An embolic microcoil can be formed into a complex shape for use in treating aneurysms and other vascular disorders. The microcoil features a distal portion including several loops that together comprise a substantially spherical shape, and an elongated proximal portion that is deployable within the distal portion. The distal portion can create a stable frame with adequate loop coverage across a neck of the aneurysm. The proximal portion can include a series of substantially omega-shaped loops, which can apply a force against the interior of the substantially spherical shaped distal portion, expanding it into apposition with additional portions of the aneurysm wall. Methods of treating vascular disorders and methods of manufacturing certain microcoils are also disclosed.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of, and incorporatesherein by reference in its entirety, U.S. Provisional Patent ApplicationNo. 61/945,567, which was filed on Feb. 27, 2014.

TECHNICAL FIELD

In general, various embodiments of this invention relate to embolicdevices for use in the minimally invasive treatment of aneurysms andother vascular disorders and, more particularly, to embolic framingmicrocoils having various novel shapes that can be used in suchtreatment.

BACKGROUND

The treatment of aneurysms and other similar vascular disorders ofteninvolves the placement of microcoils within a space formed by theaneurysm. This space is often spherical, but in some instances can beelliptical or can have two or more lobular protrusions (often calledbi-lobed or multi-lobed aneurysms). Most current microcoil systems havea variety of shapes and can include framing, filling and finishingcoils. A framing coil is the first coil placed within an aneurysm andhas a complex or three-dimensional shape designed to fit within thespace formed by the aneurysm. The framing coil can be used to performthe following functions: (1) provide a stable frame within the confinesof the aneurysm into which subsequent coils can be placed; (2) provideadequate loop coverage across a neck of the aneurysm; and (3) preventloops from crossing the center of the aneurysm (which can createcompartments within the aneurysm that require additional cathetermanipulation, prolonging the procedure and increasing the risk ofaneurysm rupture). Additionally, in some instances, it is desirable forthe framing coil to be delivered with minimal or acceptably low frictionwithin a microcatheter. Many framing coils have spherical shapes thatcan perform these functions when treating a spherical aneurysm; however,they are often inadequate when the aneurysm is non-spherical (e.g.,elliptical or bi-lobed). Other framing coils have complex shapes thatfit within non-spherical aneurysms; however, such coils typicallyconsist of loops that are arranged with independent axes and aredesigned to be constrained by the aneurysm itself. This type of shaperesults in the framing coil having significant potential energy,meaning, for example, that in its unrestrained state it expands wellbeyond the dimensions of the aneurysm and therefore transfers forcedirectly to the aneurysm wall when constrained in the space. While thisforce may not be enough to harm the aneurysm wall, it leaves the framingcoil in a state susceptible to movement upon placement of subsequentcoils. Often times, such coils will shift and potentially cause a loopto protrude into the parent artery, which requires adjunctive and/oremergency therapy. Additionally, the complex shapes of some framingcoils often increase the friction created when they are deliveredthrough a microcatheter.

Accordingly, needs exist for improved embolic framing microcoils.

SUMMARY OF THE INVENTION

In various embodiments, the present invention relates to acomplex-shaped embolic framing microcoil that can effectively bedeployed in aneurysms of a wide variety of shapes and delivered withlower friction than many existing microcoils. In an embodiment, theframing microcoil includes a distal portion having at least two loopelements that form a substantially spherical shape and an elongatedproximal portion deployable within the spherical shape and having aseries of omega-shaped loops. Such a configuration may, for example,prevent the proximal portion from protruding into the parent artery andhelp adapt the substantially spherical distal portion to fit variousaneurysm morphologies, while maintaining patency within the center ofthe aneurysm for subsequent microcoils. Although this application oftenrefers to aneurysms, it should be understood that the systems andmethods disclosed herein can be adapted for use with any vasculardisorder.

In general, in one aspect, embodiments of the invention feature aframing microcoil for use in treating a vascular disorder. The microcoilmay include a substantially spherical distal portion and a proximalportion for deployment within the substantially spherical distalportion. The proximal portion may include a series of substantiallyomega-shaped loops.

In various embodiments, the substantially omega-shaped loops alternatein orientation. In some instances, the series of substantiallyomega-shaped loops is arranged in a substantially toroid shape whendeployed within the substantially spherical distal portion. The toroidshape may be bounded by an interior of the substantially sphericaldistal portion. In certain instances, the substantially spherical distalportion and/or the proximal portion includes a wire wound to form aprimary coil. In some cases, the wire is helically wound and/or includesa platinum alloy. A cross-section of the wire may have a diameter in arange from 0.001 inches to 0.010 inches. A cross-section of the primarycoil may have a diameter in a range from 0.008 inches to 0.038 inches.In some instances, the substantially omega-shaped loops are adapted tofit within the substantially spherical distal portion. The omega-shapedloops may be adapted to bias against an interior of the substantiallyspherical distal portion.

In general, in another aspect, embodiments of the invention feature amethod for treating a vascular disorder of a patient. The method caninclude the steps of positioning a substantially spherical distalportion of a framing microcoil within the vascular disorder, anddeploying a proximal portion of the microcoil within the substantiallyspherical distal portion. The proximal portion may include a series ofsubstantially omega-shaped loops. In various embodiments, the deployingstep includes expanding the substantially spherical distal portionoutward into apposition with a wall of the vascular disorder.

In general, in yet another aspect, embodiments of the invention featureanother framing microcoil for use in treating a vascular disorder. Themicrocoil includes a substantially spherical distal portion having atleast two curved, lobe-shaped loops crossing at a common point.

In various embodiments, the common point is at a base of thesubstantially spherical distal portion. The curved, lobe-shaped loopsmay be adapted to expand outward, upon deployment of the microcoil intoa vascular disorder, into apposition with a wall of the vasculardisorder. In some instances, the curved, lobe-shaped loops are biasedoutward by another portion of the microcoil deployed within thesubstantially spherical distal portion, which may include an elongateproximal portion of the microcoil. Each curved, lobe-shaped loop mayhave a diameter in a range from 1 mm to 24 mm. The substantiallyspherical distal portion may include between three and six curved,lobe-shaped loops.

In some instances, the microcoil includes a wire wound to form a primarycoil. The wire may be helically wound and/or include a platinum alloy. Across-section of the wire may have a diameter in a range from 0.001inches to 0.010 inches. A cross-section of the primary coil may have adiameter in a range from 0.008 inches to 0.038 inches.

In some instances, the substantially spherical distal portion includesat least two nested shells. Each shell may have at least one curved,lobe-shaped loop with the curved, lobe-shaped loops crossing at thecommon point. In such instances, the nested shells can be offsetcircumferentially at an angle relative to each other (e.g., 90 degreesor 180 degrees).

In general, in still another aspect, embodiments of the inventionfeature another method for treating a vascular disorder. The methodincludes the step of positioning within the vascular disorder a framingmicrocoil that includes a substantially spherical distal portion havingat least two curved, lobe-shaped loops crossing at a common point.

In various embodiments, the method further includes the step ofexpanding at least one of the curved, lobe-shaped loops outward intoapposition with a wall of the vascular disorder. This expanding step caninclude disposing another portion of the microcoil within thesubstantially spherical distal portion. The method may further includethe steps of accessing the vascular disorder with a microcatheter, anddeploying the framing microcoil from the microcatheter into the vasculardisorder.

In general, in a further aspect, embodiments of the invention feature amethod of manufacturing a framing microcoil for use in treating avascular disorder. The method can include the steps of wrapping aprimary coil about a spherical mold having pegs to form a substantiallyspherical portion including at least two curved, lobe-shaped loopscrossing at a common point, and heating the primary coil while wrappedabout the mold to set a shape of the primary coil.

In general, in another aspect, embodiments of the invention featureanother method of manufacturing a framing microcoil for use in treatinga vascular disorder. The method can include the steps of applying amaterial to an adhesive backed medium in a predetermined patternincluding at least two curved, lobe-shaped loops that cross at a commonpoint, wrapping a substantially spherical object with the material andthe medium, heating the wrapped object to set a shape of the material,threading a primary coil onto the material, and heating the primary coilwhile threaded on the material to set a shape of the primary coil.

In various embodiments, the method can further include the step of usinga template as a guide when applying the material to the medium. Themethod can also include the step of securing the material to the object,which may include using a metal foil. In some instances, the methodincludes the step of placing the wrapped object into a hollowed-outcavity prior to heating the wrapped object. In certain instances, themethod includes the step of securing the primary coil to the object,which may include using a metal foil. In some instances, the methodincludes the step of placing the primary coil threaded on the materialinto a hollowed-out cavity prior to heating the primary coil.

In general, in yet another aspect, embodiments of the invention featureanother framing microcoil for use in treating a vascular disorder. Themicrocoil includes a substantially spherical portion that includes aseries of loops formed in a pattern having two first loops approximately90 degrees apart, a first plurality of loops formed at incrementalangles in a clockwise direction relative to a first one of the two firstloops, and a second plurality of loops formed at incremental angles in acounterclockwise direction relative to the first one of the two firstloops.

In various embodiments, the loops cross at at least one common point. Insome instances, the at least one common point includes two diametricallyopposed apex points. In one embodiment, the loops are adapted to expandoutward, upon deployment of the microcoil into a vascular disorder, intoapposition with a wall of the vascular disorder. The loops may be biasedoutward by another portion of the microcoil deployed within thesubstantially spherical portion, which may include an elongate proximalportion of the microcoil. In some instances, the microcoil includes awire wound to form a primary coil. In some cases, the wire is helicallywound and/or includes a platinum alloy. A cross-section of the wire mayhave a diameter in a range from 0.001 inches to 0.010 inches. Across-section of the primary coil may have a diameter in a range from0.008 inches to 0.038 inches.

In general, in still another aspect, embodiments of the inventionfeature another method for treating a vascular disorder. The methodincludes the step of positioning within the vascular disorder a framingmicrocoil that includes a substantially spherical portion having aseries of loops formed in a pattern. The pattern includes two firstloops approximately 90 degrees apart, a first plurality of loops formedat incremental angles in a clockwise direction relative to a first oneof the two first loops, and a second plurality of loops formed atincremental angles in a counterclockwise direction relative to the firstone of the two first loops.

In various embodiments, the method further includes the step ofexpanding at least one of the loops outward into apposition with a wallof the vascular disorder. The expanding step may include disposinganother portion of the microcoil within the substantially sphericalportion. In some instances, the method further includes the steps ofaccessing the vascular disorder with a microcatheter, and deploying theframing microcoil from the microcatheter into the vascular disorder.

In general, in a further aspect, embodiments of the invention featureanother method of manufacturing a framing microcoil for use in treatinga vascular disorder. The method includes the step of wrapping a primarycoil about a spherical mold having pegs to form a substantiallyspherical portion. The substantially spherical portion includes a seriesof loops formed in a pattern having two first loops approximately 90degrees apart, a first plurality of loops formed at incremental anglesin a clockwise direction relative to a first one of the two first loops,and a second plurality of loops formed at incremental angles in acounterclockwise direction relative to the first one of the two firstloops. The method also includes the step of heating the primary coilwhile wrapped about the spherical mold to set a shape of the primarycoil.

These and other objects, along with advantages and features of theembodiments of the present invention herein disclosed, will become moreapparent through reference to the following description, theaccompanying drawings, and the claims. Furthermore, it is to beunderstood that the features of the various embodiments described hereinare not mutually exclusive and can exist in various combinations andpermutations.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like reference characters generally refer to the sameparts throughout the different views. Also, the drawings are notnecessarily to scale, emphasis instead generally being placed uponillustrating the principles of the invention. In the followingdescription, various embodiments of the present invention are describedwith reference to the following drawings, in which:

FIG. 1 is a schematic side view of a microcoil that includes anelongated proximal portion and a substantially spherical distal portionaccording to one embodiment;

FIG. 2 is a schematic side view of a microcoil placed within an aneurysmaccording to one embodiment;

FIG. 3A is a schematic perspective view showing a wire wound to form aprimary coil according to one embodiment;

FIG. 3B is an enlarged view of a portion of FIG. 3A showing across-section diameter of a wire;

FIG. 3C is an enlarged view of a portion of FIG. 3A showing a diameterof a primary coil;

FIG. 3D is an enlarged view of a portion of FIG. 3A showing a secondarydiameter of a microcoil;

FIG. 4A is a schematic perspective view of a curved, lobe-shapedconfiguration of the distal portion of a microcoil according to oneembodiment;

FIGS. 4B and 4C are schematic side views showing curved, lobe-shapedloops having different shapes according to various embodiments;

FIGS. 5A-5E are schematic side views showing various curved, lobe-shapedloops' coverage of an aneurysm wall according to various embodiments;

FIG. 6A is a schematic side view of a distal portion of a microcoilhaving multiple shells of curved, lobe-shaped loops according to oneembodiment;

FIG. 6B is a schematic side view of a distal portion of a microcoilhaving multiple shells of curved, lobe-shaped loops offsetcircumferentially from one another by an angle according to oneembodiment;

FIG. 7 is a schematic perspective view showing a primary coil woundabout a mold to form a curved, lobe-shaped configuration according toone embodiment;

FIGS. 8A-8F are schematic perspective views that illustrate a method ofmanufacturing the distal portion of a microcoil having a curved,lobe-shaped configuration, according to one embodiment;

FIG. 9 is a schematic perspective view of a fan-shaped configuration ofthe distal portion of a microcoil according to one embodiment;

FIG. 10 is a schematic perspective view showing a primary coil woundabout a mold to form a fan-shaped configuration according to oneembodiment;

FIG. 11A is a schematic side view showing a proximal portion of amicrocoil having omega-shaped loops according to one embodiment;

FIG. 11B is a schematic perspective view showing a proximal portionhaving omega-shaped loops wrapped in a toroid shape about a distalportion of a microcoil, according to one embodiment; and

FIG. 11C is a schematic top view showing a proximal portion havingomega-shaped loops wrapped in a toroid shape about a distal portion of amicrocoil, according to one embodiment.

DESCRIPTION

Embodiments of the present invention are directed to a complex-shapedembolic framing microcoil, which may include a distal portion and aproximal portion that together form one continuous primary coil. Thedistal portion may include several individual elements or loops thattogether form a substantially spherical shape, and the proximal portionmay include several elements that form an elongated shape. FIG. 1 showsan exemplary microcoil 102 having a distal portion 104 formed of curved,lobe-shaped loops and a proximal portion 106 formed of omega-shapedloops. However, as will be discussed below, the distal portion 104 andproximal portion 106 may be formed in other shapes as well.

With reference to FIG. 2, in one embodiment the microcoil 102 isinserted into an aneurysm 202 (or cavity associated with a similarvascular disorder) such that the distal portion 104 creates a stableframe with adequate loop coverage across a neck 204 of the aneurysm 202.In some instances, the distal portion 104 forms a substantiallyspherical shape. Following deployment of the distal portion 104, theproximal portion 106 can be deployed within the frame created by thedistal portion 104. Both the distal and proximal portions can, in somecases, be deployed by extrusion through a microcatheter. Once deployed,elongated loops of the proximal portion 106 can gently push against aninterior of the previously placed substantially spherical distal portion104, and expand individual loop elements of the distal portion outward.For some aneurysms 202 (e.g., spherically shaped aneurysms), the distalportion 104 may be deployed in apposition with the aneurysm wall 206. Insuch instances, there may not be room for the distal portion 104 to besignificantly expanded by the elongated proximal portion 106, andpatency will be maintained in the center of the microcoil mass. Forother aneurysms 202 (e.g., irregularly shaped aneurysms), the elongatedproximal portion 106 expands certain loops or elements of the distalportion 104 outward to ensure apposition of the coil loops and theaneurysm wall 206.

Referring to FIG. 3A, in some embodiments, the framing microcoil 102 isgenerally made from wire 302 having a cross-sectional diameter 310 (asshown in FIG. 3B) that is between approximately 0.001″ and 0.010″, andthe wire 302 is wound over a mandrel to create a primary coil 304 with adiameter 312 (as shown in FIG. 3C) between approximately 0.008″ and0.038″. For neurovascular aneurysms, the cross-sectional diameter 310 ofthe wire 302 may be between approximately 0.001″ and 0.004″, and thewire 302 can be wound to create a primary coil 304 having across-sectional diameter 312 between approximately 0.008″ and 0.018″. Insome instances, the wire 302 is helically wound to form the primary coil304. In some cases, the wire 302 includes a platinum alloy (e.g.,platinum/tungsten). The primary coil 304 can then be wound into variousshapes (e.g., loops) having a secondary diameter 306 (as shown in FIG.3D).

FIG. 3A shows the primary coil 304 wound into three curved, lobe-shapedloops. However, as will be discussed below, in other embodiments theprimary coil 304 is wound into other shapes having various secondarydiameters. The cross-sectional diameters of the wire 310 and the primarycoil 312 can be adjusted to optimize softness (e.g., compliancy andresiliency) for a microcoil having a given secondary diameter 306.

In one embodiment, and with reference still to FIG. 3A, the microcoilalso includes a stretch-resistant inner member 308. The inner member 308can be made from a biocompatible material that adds minimal stiffnessbut that provides tensile strength, for example a polymer such asmonofilament polypropylene.

FIG. 4A shows the substantially spherical distal portion 104 of themicrocoil 102 according to one embodiment of the invention. The distalportion 104 includes the primary coil 304 formed into a series ofcurved, lobe-shaped loops 402. A curved, lobe-shaped loop 402 is aportion of the primary coil 304 shaped such that is has a beginningpoint 404, a curved section 406 having an apex 412, and an end point 408that crosses the beginning point 404. The curved, lobe-shaped loopsinclude a secondary diameter 306. The secondary diameter 306 of thecurved, lobe-shaped loops can vary in different embodiments of theinvention. For example, the curved, lobe-shaped loop 402 shown in FIG.4B has a larger secondary diameter 306 than the secondary diameter 306of the curved, lobe shaped-loop 402 shown in FIG. 4C. Generallyspeaking, if the primary diameter 312 remains constant, as the secondarydiameter 306 of a microcoil increases, the friction within amicrocatheter upon insertion of the microcoil decreases. This isexplained by the fact that friction decreases as stiffness decreases,and the k-factor for stiffness of the microcoil is proportional to thefollowing ratio: primary diameter/secondary diameter. In other words,the stiffness of the microcoil is inversely proportional to thesecondary diameter. Thus, the friction within a microcatheter uponinsertion of the microcoil is inversely proportional to the secondarydiameter 306. Further, applying a similar concept, if the wire diameter310 remains constant, as the primary diameter 312 increases, thefriction within the microcatheter upon insertion of the microcoilgenerally decreases. This is because the k-factor for stiffness is alsoproportional to the following ratio: wire diameter/primary diameter. Thesize of each curved, lobe-shaped loop can be optimized to provideacceptable friction upon insertion into a microcatheter, as well asadequate aneurysm wall coverage.

In some instances, the distal portion 104 includes at least two curved,lobe-shaped loops 402. The number of curved, lobe-shaped loops 402 canvary depending on the secondary diameter 306 and the length of themicrocoil used. The beginning and end points of all curved, lobe-shapedloops can cross at a common point 410. In some cases, as shown in FIG.4A, the common point 410 is located at a base of the distal portion 104.Every other curved, lobe-shaped loop may have a secondary diameter 306that is equal to or greater than the diameter of the aneurysm intendedfor embolization. In some instances, each curved, lobe-shaped loop 402has the same secondary diameter 306. As an example, the secondarydiameter 306 can be in a range from 1 mm to 24 mm. In other instances,different curved, lobe-shaped loops 402 have different secondarydiameters 306.

In some embodiments, upon deployment of the elongated proximal portion106 within the distal portion 104, force is exerted by the elongatedproximal portion 106 against an interior of the distal portion 104 andeach curved, lobe-shaped loop 402 expands outward to fill open space inthe aneurysm 202. The number of curved, lobe-shaped loops 402, theheight of each curved, lobe-shaped loop 402 (e.g., the distance betweenthe beginning point 404/ending point 408 and the apex 412 of the curvedsection 406), and the shape of each curved, lobe-shaped loop (e.g., itssecondary diameter 306) can all be varied to achieve various amounts ofcoverage on the aneurysm's interior wall 206, as demonstrated in FIGS.5A-5E. Depending on the size of the microcoil used, various numbers ofcurved, lobe-shaped loops 402 may be required to cover the interior wall206 of a given aneurysm 202. For example, primary coils 304 formed intoshapes to fit smaller aneurysms may only require three or four curved,lobe-shaped loops 402, while primary coils 304 formed into shapes to fitlarger aneurysms may require four, five or six curved, lobe-shaped loops402.

In some embodiments, depending on the length of the microcoil used, itmay also be desirable to create a shape having overlapping or nestedcurved, lobe-shaped loops 402. In such embodiments, the curved,lobe-shaped loops 402 can be arranged in two or more shells, with someshells being nested within other shells. For example, as shown in FIG.6A, a particular distal portion 104 may include multiple curved,lobe-shaped loops 402, with some curved, lobe-shaped loops in an innershell 602 overlapping (e.g., nested within) other curved, lobe-shapedloops in an outer shell 604. In such embodiments, all the curved,lobe-shaped loops located in every shell can cross at a common point,which in some instances is located at a base of the distal portion 104.In some instances, as shown in FIG. 6B, the shells of curved,lobe-shaped loops may be offset circumferentially from one another suchthat there is a circumferential angular offset between curved,lobe-shaped loops of different shells. The angular offset can generallybe any desired angle, for example 20 degrees, 30 degrees, 45 degrees, 60degrees, 90 degrees or 180 degrees. At times throughout thisapplication, the configurations of the distal portion 104 described withreference to FIGS. 4A-6B are referred to as “curved, lobe-shaped”configurations.

Another aspect of the invention includes a method for manufacturing aframing microcoil having a curved, lobe-shaped configuration for use intreating a vascular disorder. As shown, for example, in FIG. 7, themethod can include obtaining a substantially spherical mold 702 havingpegs 704. The method can include wrapping a primary coil 304 about thepegs 704 to form a desired shape (e.g., curved, lobe-shaped loopscrossing at a common point). The entire assembly (primary coil 304wrapped about mold 702) can be placed into a high temperature oven toheat set the primary coil 304 into shape. The heating operation can havea shape-set time in a range from 30-180 minutes and a shape-settemperature in a range from 400° C. to 800° C.

Another aspect of the invention includes another method formanufacturing a framing microcoil having a curved, lobe-shapedconfiguration for use in treating a vascular disorder. As shown in FIG.8A, the method can include applying a material 802 (e.g., nitinol wire)to an adhesive backed medium 804 (e.g., an adhesive tape) in apredetermined pattern. In some instances, the pattern includes at leasttwo curved, lobe-shaped loops that all cross at a common point. In someinstances, the adhesive backed medium 804 includes a template of thepattern for use as a guide when applying the material 802 to the medium804. As shown in FIGS. 8B and 8C, the method can include placing a firstsubstantially spherical object 806 in the center of the pattern, andlifting the adhesive backed medium 804 to wrap the material 802 aboutthe first substantially spherical object 806. In certain cases, thefirst substantially spherical object 806 includes stainless steel. Insome embodiments, the material 802 is secured to the first substantiallyspherical object 806 by wrapping a securing item 810 (e.g., aluminumfoil) around the material 802 and the first substantially sphericalobject 806. In other embodiments, the material 802 is secured to thefirst substantially spherical object 806 by placing the material 802 andthe first substantially spherical object 806 into a hollowed out cavity.The resulting assembly (material 802 adhered to first substantiallyspherical object 806) can be placed into a high temperature oven to heatset the material 802 into shape. The heating operation can have the sameparameters as described above.

Once heat set into shape, the material 802 can be removed from the firstsubstantially spherical object 806, as shown in FIG. 8D. The method canthen include threading a primary coil 304 onto the heat set material802, as shown in FIG. 8E. The primary coil 304 threaded onto heat setmaterial 802 can then be wrapped about a second substantially sphericalobject 808, as shown for example in FIG. 8F, and secured thereto usingthe same techniques for wrapping and securing the material 802 about thefirst substantially spherical object 806. In some cases, the secondsubstantially spherical object 808 includes stainless steel. In someembodiments, the first substantially spherical object 806 and the secondsubstantially spherical object 808 are the same object. In otherembodiments, the first substantially spherical object 806 and the secondsubstantially spherical object 808 are different objects. The resultingassembly (primary coil 304 secured to second substantially sphericalobject 808) can be placed into a high temperature oven to heat set theprimary coil 304 into shape. The heating operation can have the sameparameters as described above.

FIG. 9 shows another exemplary configuration of the substantiallyspherical distal portion 104 according to an embodiment of theinvention. The distal portion 104 includes the primary coil 304 woundinto a series of loops forming a pattern. The pattern includes two firstloops 902, 904 approximately 90 degrees apart. The pattern also includesa first plurality of loops 906 formed at incremental angles in aclockwise direction from one of the first two loops (e.g., loop 902),and a second plurality of loops 908 formed at incremental angles in acounterclockwise direction from one of the first two loops (e.g., loop902). In some instances, each of the loops in the first plurality ofloops 906 are separated from one another by the same incremental angle.Similarly, in some instances, each of the loops in the second pluralityof loops 908 are separated from one another by the same incrementalangle. In other instances, the loops in the first plurality of loops 906are separated from one another by different incremental angles.Similarly, in some implementations, the loops in the second plurality ofloops 908 are separated from one another by different incrementalangles. In some embodiments, the series of loops may cross at at leastone common point. In some instances, the at least one common pointincludes two diametrically opposed apex points 910, 912 of thesubstantially spherical distal portion 104. At times throughout thisapplication, the configurations of the distal portion 104 described withreference to FIG. 9 are referred to as “fan-shaped” configurations.

Another aspect of the invention includes a method for manufacturing aframing microcoil having a fan-shaped configuration for use in treatinga vascular disorder. As shown, for example, in FIG. 10, the method caninclude obtaining a mold 1002 having pegs 1004. The method can includewrapping a primary coil 304 about the pegs 1004 to form a pattern (e.g.,the fan-shaped configuration). The entire assembly (primary coil 304wrapped about mold 1002) can then be placed into a high temperature ovento heat set the primary coil 304 into shape. The heating operation canhave the same parameters as described above.

As discussed above, certain embodiments of the invention feature amicrocoil 102 that includes a distal portion 104 (e.g., having a curved,lobe-shaped configuration or a fan-shaped configuration) as well as aproximal portion 106. In some embodiments, the proximal portion 106includes omega-shaped loops 1102A, 1102B, as shown for example in FIG.11A. The omega-shaped loops can be formed of a primary coil 304 woundinto the loops 1102A, 1102B. With reference to FIG. 11A, an omega-shapedloop includes two legs 1104, a connecting portion 1108 that connects afirst end of the two legs 1104, and an incomplete portion 1110 betweenthe second end of the two legs. The legs 1104 can be resilient and/orcompliant. In some instances, the omega-shaped loops can alternate inorientation from one another. For example, the omega-shaped loops 1102Aalternate in orientation from the omega-shaped loops 1102B. FIG. 11Ashows the distal portion 104 as having a curved, lobe-shapedconfiguration. In general, however, the distal portion 104 connected tothe omega-shaped loops can have any configuration, for example thefan-shaped configuration or another substantially sphericalconfiguration. In some embodiments, the proximal portion 106 includingthe omega-shaped loops 1102A, 1102B is adapted to be deployed within thedistal portion 104 to impose a gentle outward force from within theloops of the initially deployed distal portion 104. In some cases, suchforce can: (1) help stabilize the entire framing infrastructure; (2)significantly enhance the probability of framing irregularly shaped,non-spherical aneurysms (e.g., bi-lobed, ellipsoidal, etc.) by castingor biasing the loops of the distal portion 104 into outer spaces of theaneurysm; (3) increase frame stability within wide-neck aneurysms;and/or (4) maximize the distal portion's contact with the aneurysm wallwhile minimizing the presence of loops crossing through the centralspace of the aneurysm.

It can be desirable for the proximal portion 106 to feature omega-shapedloops (or other incomplete loops), because such shapes are better atadapting to various amounts of space within the frame formed by thedistal portion 104 than shapes such as complete helical loops. Forexample, a complete helical loop, if sized too large, may twist orcompress toward the center of the space it is filling, which can lead tocompartmentalization. If the complete helical loop is sized too small,it may fill the center of the aneurysm, again leading tocompartmentalization. Conversely, an omega-shaped loop includes legs1104 that are resilient and/or compliant such that they can be tuned(e.g., spread further apart or pushed closer together) to adjust thesize of the omega-shaped loops. Adjustment of the size of theomega-shaped loops can allow them to fit appropriately within distalportions of varying sizes. In some embodiments, the size of eachomega-shaped loop is set during manufacture of the omega-shaped loops(as described below) to fit a distal portion 104 of a particular size.In other embodiments, each omega-shaped loop is manufactured to astandard size, and following disposal of the proximal portion 106 withinthe distal portion 104, the legs 1104 are adapted to move to improve thefit of the proximal portion 106 within the distal portion 104. In someinstances, the spacing between the legs of each omega-shaped loop issubstantially the same. In other instances, the spacing between the legsof the omega-shaped loops differ from one another.

FIG. 11A is a schematic drawing that illustrates the general shape ofthe omega-shaped loops; however, FIG. 11A does not depict theorientation of the omega-shaped loops when disposed within the distalportion 104. Examples of such orientations are shown in FIGS. 11B and11C. As shown, when disposed within the distal portion 104, theomega-shaped loops can be arranged as if they are shaped around asubstantially torus or toroid shape, such that they track the shape ofthe distal portion 104 along the interior of the distal portion 104. Inorder to clearly depict the omega-shaped loops, FIGS. 11B and 11C depictthe omega-shaped loops in a substantially toroid shape along theexterior of the distal portion 104. In reality, however, when deployed,the omega-shaped loops track the interior of the distal portion 104,such that they can apply an outward force to the interior of the distalportion 104.

Another aspect of the invention includes a method for manufacturing theproximal portion 106 including the omega-shaped loops 1102A, 1102B. Themethod can include obtaining a substantially toroid-shaped object thatincludes an omega-shaped pattern. This may involve machining anomega-shaped pattern into the substantially toroid-shaped object. Thesubstantially toroid-shaped object can then be combined with asubstantially spherical object, which may involve wrapping thesubstantially toroid-shaped object around the substantially sphericalobject. A primary coil 304 may then be threaded onto the omega-shapedpattern on the substantially toroid-shaped object. The resultingassembly (primary coil 304 threaded onto the omega-shaped pattern on thesubstantially toroid-shaped object wrapped around the substantiallyspherical object) can then be placed into a high temperature oven toheat set the primary coil 304 into shape. The heating operation can havethe same parameters as described above.

Other aspects of the invention include methods for treating a vasculardisorder that include positioning a microcoil 102 within the vasculardisorder. In general, a microcoil 102 may be introduced, delivered,positioned, and implanted within a vascular disorder using amicrocatheter. The microcatheter can be a flexible, small diametercatheter having, for example, an inside diameter between 0.016 inchesand 0.021 inches. The microcatheter may be introduced by an introducersheath/guiding catheter combination placed in the femoral artery orgroin area of a patient. In some instances, the microcatheter is guidedinto the vascular disorder with guidewires (e.g., long, torqueableproximal wire sections with more flexible distal wire sections designedto be advanced within tortuous vessels). Such guidewires may be visibleusing fluoroscopy and may be used to first access the vascular disorder,thereby allowing the microcather to be advanced over it into thedisorder.

In some instances, once the tip of the microcatheter has accessed thevascular disorder, the guidewire is removed from the catheter lumen. Themicrocoil 102 may then be placed into the proximal open end of themicrocatheter and advanced through the microcatheter with a deliverymechanism. While the microcoil 102 is disposed within the lumen of themicrocatheter it takes the form of a straightened out primary coil. Auser (e.g., a physician) may advance and/or retract the microcoil 102several times to obtain a desirable position of the microcoil 102 withinthe disorder. Once the microcoil 102 is satisfactorily positioned, itcan be released into the disorder. Upon release, the primary coil mayform a secondary shape, for example the curved, lobe-shapedconfiguration, fan-shaped configuration, or any other desiredconfiguration. In some instances, the primary coils' formation of asecondary shape upon deployment into the vascular disorder is caused bythe shape-memory nature of the material used to form the microcoil(e.g., nitinol wire). In some instances, the vascular disorder treatedis an aneurysm (e.g., a cerebral aneurysm).

In some embodiments, the method for treating a vascular disorderincludes positioning, within the vascular disorder, a substantiallyspherical distal portion 104 of a microcoil 102, and then deploying,within the distal portion 104, a proximal portion 106 of the microcoil102 having a series of substantially omega-shaped loops. Both the distalportion 104 and proximal portion 106 may be positioned and/or deployedusing the techniques described above. In some embodiments, the distalportion 104 includes the curved, lobe-shaped configuration. In otherembodiments, the distal portion 104 includes the fan-shapedconfiguration. In some instances, deploying the proximal portion 106includes imposing an outward force from within the distal portion 104.

Having described certain embodiments of the invention, it will beapparent to those of ordinary skill in the art that other embodimentsincorporating the concepts disclosed herein may be used withoutdeparting from the spirit and scope of the invention. Accordingly, thedescribed embodiments are to be considered in all respects as onlyillustrative and not restrictive.

What is claimed is:
 1. A framing microcoil for use in treating avascular disorder, the microcoil comprising: a substantially sphericalportion comprising a series of loops formed in a pattern comprising twofirst loops approximately 90 degrees apart, a first plurality of loopsformed at incremental angles in a clockwise direction relative to afirst one of the two first loops, and a second plurality of loops formedat incremental angles in a counterclockwise direction relative to thefirst one of the two first loops.
 2. The framing microcoil of claim 1,wherein the loops cross at at least one common point.
 3. The framingmicrocoil of claim 2, wherein the at least one common point comprisestwo diametrically opposed apex points.
 4. The framing microcoil of claim1, wherein the loops are adapted to expand outward, upon deployment ofthe microcoil into a vascular disorder, into apposition with a wall ofthe vascular disorder.
 5. The framing microcoil of claim 4, wherein theloops are biased outward by another portion of the microcoil deployedwithin the substantially spherical portion.
 6. The framing microcoil ofclaim 5, wherein the another portion comprises an elongate proximalportion of the microcoil.
 7. The framing microcoil of claim 1, whereinthe microcoil comprises a wire wound to form a primary coil.
 8. Theframing microcoil of claim 7, wherein the wire is helically wound. 9.The framing microcoil of claim 7, wherein the wire comprises a platinumalloy.
 10. The framing microcoil of claim 7, wherein a cross-section ofthe wire comprises a diameter in a range from 0.001 inches to 0.010inches.
 11. The framing microcoil of claim 7, wherein a cross-section ofthe primary coil comprises a diameter in a range from 0.008 inches to0.038 inches.
 12. A method for treating a vascular disorder, the methodcomprising the step of: positioning within the vascular disorder aframing microcoil comprising a substantially spherical portioncomprising a series of loops formed in a pattern comprising two firstloops approximately 90 degrees apart, a first plurality of loops formedat incremental angles in a clockwise direction relative to a first oneof the two first loops, and a second plurality of loops formed atincremental angles in a counterclockwise direction relative to the firstone of the two first loops.
 13. The method of claim 12, wherein theloops cross at at least one common point.
 14. The method of claim 13,wherein the at least one common point comprises two diametricallyopposed apex points.
 15. The method of claim 12, further comprising thestep of expanding at least one of the loops outward into apposition witha wall of the vascular disorder.
 16. The method of claim 15, wherein theexpanding step comprises disposing another portion of the microcoilwithin the substantially spherical portion.
 17. The method of claim 12,further comprising the steps of: accessing the vascular disorder with amicrocatheter; and deploying the framing microcoil from themicrocatheter into the vascular disorder.
 18. A method of manufacturinga framing microcoil for use in treating a vascular disorder, the methodcomprising the steps of: wrapping a primary coil about a spherical moldcomprising pegs to form a substantially spherical portion comprising aseries of loops formed in a pattern comprising two first loopsapproximately 90 degrees apart, a first plurality of loops formed atincremental angles in a clockwise direction relative to a first one ofthe two first loops, and a second plurality of loops formed atincremental angles in a counterclockwise direction relative to the firstone of the two first loops; and heating the primary coil while wrappedabout the spherical mold to set a shape of the primary coil.